Oddly enough I don't know anyone in real life that has had a baby in the last few years that actually breastfed at all. Everyone has gone right to the bottle.

Reasons I have heard..
Going back to work right after or shortly after giving birth.
Bottles allow Dad to help with the feeding
Can't drink and breastfeed
People said it hurts
Not stuck with the baby and having to be "on call" for its feedings. Allows mom more freedom to travel, attend social events without bringing baby, ect
I personally find that women of previous generations discourage it. I can't tell you how many times I have heard a women 50 or older tell someone that they shouldn't breastfeed.